The present invention deals with a snap fastener comprising male and female elements in the form of a button, which fastener is used to unite two generally flexible laminae, such as fabrics, garments, tent cloths and the like.
The snap fastener of this invention has been improved in an extraordinary manner, overcoming the disadvantages of the known fasteners, inasmuch as same cannot be opened accidentally, for instance by the effect of involuntary forces or pulls exerted on the united sheets. The improved snap fastener thus assures a perfect closing of the garments or other articles, without the possibilty of an undesired occasional opening. Nevertheless, if desired, the improved snap fastener can be opened easily, operating like a pushbutton, attaining thereby the quick disengagement of the male and female elements without the necessity to pull the laminae or exert forces towards the sides, such as normally happens with known fasteners when they have to be opened in order to separate the laminae.
It is also an object of the present invention to place the snap fastener on any flexible lamina without having to make a hole in the lamina, thereby simplifying the mounting operation.
In the present invention, the two exterior parts forming the female element have clamps and pins which go through the flexible lamina, whereby the holes caused by the perforation of the lamina are hidden because of the piercing clamps and pins being positioned inwardly from the border of the element. More specifically, the snap fastener of this invention is characterized by the fact that the female element is constituted by two elements, namely an upper piece placed on the top of the flexible lamina and a lower piece placed below the same and both in perfect coincidence.
The upper element includes an exterior visible piece of cylindrical shape, which piece is folded in the way of a curl on the edge so as to form a flange for the inner piece, thereby attaining the engagement of both pieces which form a receptacle or box with central openings in the upper and lower parts, so that in its interior there can be clamped a pushing element to facilitate the opening operation of the snap fastener. Said pushing element can adopt the most practical and useful forms to guarantee an ulimited lifetime and an easy and acceptable touch.
The inner piece is provided with a cylindrical part (to guide the piercing clamps), followed by a conical-shaped part (to fold said clamps or legs) and afterwards with a peripheral wing on which is engaged the curl of the exterior piece, leaving the necessary and sufficient space so that the folded clamps or pins can be properly placed.
The lower element of the female part is also formed by two substantially cylindrical pieces coupled together by a curl on the edge of the outside cylindrical piece, which pieces form a receptacle or box with openings in the upper and lower parts, which receptacle is adapted to contain and engage therein a third piece described herebelow.
The inside cylindrical piece of his lower element has, near its periphery triangular teeth or pins disposed vertically and positioned to perforate the flexible lamina, being inserted into the upper piece by pressure between both elements, whereby these elements are fixedly mounted to the flexible lamina.
The above-mentioned third piece consists of a disc made of a flexible (resilient) material and formed of a crownlike shape. On the disc periphery are lugs which extend at a right angle with respect to the surface of the disc, which lugs have inwardly extending fingers on the ends thereof.
This flexible disc can assume the form of an inwardly or outwardly arched piece, depending on whether a force is exerted from the top or the bottom, passing in the first case from concave to convex and vice versa in the second case, being both perfectly stable positions and entraining in their movement the lugs which are being moved towards or away from the center of the disc. When moving toward the center, the fingers of the lugs enter into a peripheral groove on the male piece of the fastener, remaining engaged therewith. By exerting pressure on the upper part or by the pusher, the flexible disc passes over center, whereby the lugs are moved away from the groove in the male element, thereby liberating same.
The above description will be more fully appreciated by reference to the following detailed description of an embodiment in accordance with the present invention when taken in conjunction with the accompanying drawings .